Click on the exhibit button below. Assume the following:
- The protected path is R1-R2-R3-R6.
- Fast reroute one-to-one protection is enabled.
If the original LSP already has two labels, and router R2 has failed, how many labels will there be in packets on the detour path?
When a fast reroute (FRR) one-to-one protection is enabled, and the original LSP already has two labels, an additional label is added for the detour path. Therefore, there will be three labels in the packets on the detour path after router R2 has failed.
Correct Answer: B Facility backup takes advantage of the MPLS label stacking capability and uses a third label to encapsulate the protected traffic and carry it through the bypass tunnel. Note that the traffic encapsulation mechanism used is different from the encapsulation used for one-to-one backup.
I think is C FRR add a new label in the detour path
Only when FRR facility is used, the correct answer is B
The question says FRR is used so I think C is the answer
no, don't believe so - it's not facility backup which is where you'd have the additional label i.e. 3